1. Field of the Invention
The present invention relates to a ceramic package for headlamp and a headlamp module having the same, and more particularly, to a ceramic package for headlamp and a headlamp module having the same, which can improve the heat dissipation characteristics by smoothly releasing heat from the ceramic package coupled to the heat transfer metal substrate.
2. Description of the Related Art
In general, a Light Emitting Diode (LED) refers to a semiconductor device capable of emitting various colors by creating a light emitting source using compound semiconductor material of GaAs, AlGaAs, GaN, InGaInP, etc.
As light sources using the LED emerge one after another, small-sized packages, which were developed for a mobile device at first, are being increasingly used for a large-sized TV, an advertizing board, an illuminator, a headlamp for vehicles, etc. Accordingly, the size of the package is being steadily increased.
In such an environment, the package requires a different structure from typical semiconductor packages because the package embedded with a LED should exert high efficiency, high reliability, thermal and electrical reliability, and optical characteristics.
Generally, a related art package using a low-power and low-output LED includes a metal plating layer on a plastic material because plastic may be easily processed in a desired reflection angle and structure.
Recently, as development of a high-power and high-output LED for general illuminators and automobile headlamps is being progressed, a material having excellent heat resistance and heat transfer property becomes required. A ceramic has been spotlighted as a material capable of meeting the requirements.
Among the ceramics, the high temperature co-fired ceramic (HTCC) having the excellent thermal characteristics has been more widely used than the low temperature co-fired ceramic (LTCC) focused on the delivery and protection function of signal.
The performance of the light emitting diode is highly dependent on the heat transfer characteristics. Also, the optical output may be increased due to the excellent heat transfer characteristics if a low temperature is maintained despite the same amount of current flow. Accordingly, the heat transfer characteristics are very important to the light emitting diode.
As a method of attaching ceramic package to a module, a surface mount device (SMD) type is widely used. According to this method, both negative and positive polarities coexist on the bottom surface because a typical lead does not protrude to the outside.
If the both polarities coexist on the same plane, a non-conductive insulating layer must necessarily be intervened between the ceramic package and the heat transfer metal substrate. This may cause deterioration of the heat transfer characteristics.